Metal alkaryl sulfonates and method



United States Patent Ufifice 21,807,590 Patented Sept. 24, 1957 METAL ALKARYL SULFONATES AND METHOD F PREPARING SAME N 0 Drawing. Application March 7, 1956,

Serial No.1 590,414

s Claims. (or. 252-353 The present invention relates to alkali and alkaline earth metal alkylated aryl sulfonates and more particularly to mixtures comprising such sulfonates having improved surface active properties.

Alkali and alkaline earth metal alkaryl sulfonates, also known as synthetic sulfonates to dilferentiate them from the mahogany or natural sulfonates, have been manufactured in large quantities by a process involving sulfonation of a suitable alkaryl hydrocarbon followed by neutralization of the resulting sulfonic acid with a base. Since sulfonation procedures are well known to those skilled in the art, those processes will not be described here. Although synthetic sulfonates possess many desirable properties ascompared to the mahogany sulfonates, they are deficient in certain other properties. As for example, the surface active properties of the synthetic sulfonates, including detergency and the tendency of the reaction mixture to split out the aqueous layer slowly and incompletely during the conversion of the sodium alkaryl sulfonate to an alkaline earth metal alkaryl sulfonate in metathesis reactions are less desirable than similar properties of the mahogany sulfonates.

It is, therefore, a principal object of this invention to provide an alkali or alkaline earth metal alkaryl sulfonate composition which obviates the disadvantages of the prior art compositions. It is another object of our invention to provide a process whereby alkali and alkaline earth metal alkaryl sulfonates can be prepared having improved surface active properties. Other objects and advantages of the present invention will be apparent from the following description.

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

Broadly stated, the present invention comprises a method whereby the surface active properties of alkali and alkaline earth metal salts of an alkaryl sulfonic acid having an average molecular weight within the range of 425-475 may be improved by incorporating in the aforesaid alkaryl sulfonates 3 to 50 Weight percent based on the weight of the alkaryl sulfonate, a mixture consisting of a high and a low molecular weight alkali or alkaline earth metal mahogany sulfonate. In many cases the surface active properties of the synthetic sulfonate can be increased by adding the high molecular weight mahogany sulfonate thereto alone. A high molecular weight metal mahogany sulfonate for the purposes of this invention is the metal salt of a mahogany sulfonic acid having an average molecular weight within the range of 450-500. A low molecular weight metal mahogany sulfonate is the metal salt of a mahogany sulfonic acid having an average molecular weight within the range of 350 100. We have found that the higher the molecular weightof the mahogany sulfonate the smaller the quantity required to give our desired results. For example, if weight percent of a mahogany sulfonate prepared from a sulfonic acid having an average molecular weight of 475 is required, the same result may be obtained using 5 weight percent of a mahogany sulfonate prepared from a sulfonic acid have an average molecular weight of 500. As to the amount of each of the mahogany sulfonates in the mixture, we have found that it may vary from 50 to 100 weight percent of the high molecular weight mahogany sulfonate and 50 to 0 weight percent of the low molecular weight mahogany sulfonate.- Obviously the amount of the two mahogany sulfonates or either one incorporated in the alkaryl sulfonate may be increased without detrimental effects if such a procedure becomes desirable for any reason.

Before proceeding with the specific examples illustrating our invention, it may be well toindicate in general the types of compounds utilized in preparing these compositions.

Suitable alkali and alkaline earth metal alkaryl sulfonates that may be used include those formed by alkylating benzene, toluene, xylenes, cumene, naphthalene, alkylnaphthalene, diphenyl, alkyldiphenyl, and the halogen derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene followed by sulfonation and finally by neutralization with an alkali or alkaline earth metal base. The alkylation may be made under the influence of a catalyst with alkylating agents from about 3 to more than 20 carbon atoms as for example, haloparafiins, olefins as from dehydrohalogenated haloparafiins, poly'olefins such as for example polymers from ethylene, propylene, butylene, ethylene and propylene, alkylsulfates, aliphatic alcohols and others. The.catalyst may be sulfuric acid, hydrofluoric acid, phosphorous containing catalysts, aluminum chloride, boron fluoride alone or with activators such as hydrogen fluoride or hydrogen chloride. Other hydro-.

carbons that may be used are raw petroleum distillate or fractions either subjected to selective solvent action or not. A particularly suitable alkaryl hydrocarbon is the compound called postdodecylbenzene which is a mixture of monoalkylbenzene and dialkylbenzenes in the approximate ratio of 2:3. Its typical physical properties are as follows:

Specific gravity at 38 C 0.8649 Average molecular weight 385 Percent sulfonatable 88 A. S. T. M., .D-l58 Engler:

I. B. P F 647 5 F 682 50 F 715 90 F 760 F.. 775 F. B. P F 779 Refractive index at 23 C 1.4900 Viscosity at:

l0 C centipoises 2800 20 C 280 40 C 78 80 C 18 Aniline point C 69 Pour point F -25 catalytic oxidation of sulfur dioxide may also be used.

The sulfur trioxide may be used undiluted in liquid or gaseous form but it is preferable to use an inert gas as a diluent.

gen, sulfur dioxide or methanemay be used. Concen- S03 content as is available Thus, sulfur trioxide diluted with air, nitrocentration of less than 10%.

asozsso,

ing temperature. With increasing viscosity local overheating takes place with subsequent charring because (of increased mixing difliculties. As the reacting temperature is raised above about 60 0., there. is increasing charring.

and resulting darkening of product.

For some sulfonations it, is. advantageous touse a. diluent for. the material being sulfonated. Examples of.

such diluents are pentane hexane, benzene, mineral'oil's and .dioxane.

trali'zing. mahogany .sul'fonic, acids having average. mo. lecular weights within the-rangeof 450 to. 500.. Ma-

hogany sulfonic acids are obtained as a by-product in the... manufacture of .white oil by sulfonatingpetroleum. oil

stocks. a

A sodium mahogany sullfonate, having an averagev mo.-

7 leeular weightof about 525 (mahogany sulfonic' acid, average molecular weightSOO) was prepared by sulfonating followed by neutralizing Withsodiumahydroxide a. solvent extracted coastal. Pale oil. a Physical properties;

of this coastal Pale oil were as follows:

A. P.'I. gravity 25.0 min. Robinson color 9/11. Flash: H

Open cup; 455 min. Cloud point 60 F. max- Pour. point 30 max. Viscosity, S. S. U., atjlO..- F. 900/925. Viscosity index' 60 min.

Neutralization No 0.10 max.

Mahogany sulfonatesv of, thedesired :average molecular weights mayjbe prepared ,by neutralization of mahogany sulfonic acids having average .molecular .weight within the range .of about-45010. 500 which in. turn may ;be.pre-. pared from a wide lubricating oil out oij=naphthenic origin by redistillation under a vacuum. The first fractions-so. obtained after sulfonation will have'an average molecular weight of about 450. The average 'molecular weights ofeach succeeding fraction after sulfonation will bev progressively higher thelast fraction being about 500.;

Suitable low molecular weight alkaliand alkalineearth metal mahogany sulfonates'areprepared-by neutnalizing acid with the appropriate. base... .Alkaline. earth metal alkaryl 0.1 mahogany. ..s,u1fonates. fwere..prepared by a metathesis reaction involving sodium alkaryl or mahogany V sulfonate and an alkaline earth metal chloride.

lnl-order. to .disclosethe nature of the present invention V v Suitable high molecular weight alkali and alkaline earthmetal mahogany) sulfonatesjare prepared by .neu

still more clearly the following illustrativejexamples-will begiven; Itzis to'be understood that theinvention is not tobejimited, tothe specific conditions ordetails set forth injhesegexaniplesexcept V V V inthe; appended claimsJPartsigiven are parts by weight.-

EXAMPEE I', "Asd ustrative of} the. value ofour cOmpQsitiQnsFin 932 9. qr m pn n r ac ions as. such limitations are specified hefollowingexperiments were conducted: sodium postdodecylbenzene sulfonate was diluted with a suflicientquantity'of 100 Pale' oil to" form a 40 percent active postdodecylbenzene sulfonate solution. Eighty parts oflbarium chloride dissolved in 260 parts of water was then added with agitation'to 400 parts of:..'th'e. sulfo'natejg solution. The mixture was then allowed to settle,-'-thus forming two layers. After standing for a period urges minutes the upper layer, compris ing;barium-.p.ostdodecylbenzene sulfonate,.was hazy and there was an emulsion cufi at the interface The experiment was then repeated with the exception that :16 parts of a'sodium salt of a mahogany sulfonic acid having an .average moleculanweighthf 470,.Was added to the 400 parts of the sodium postdodecylbenzene solution. The resulting mixture after standing'for a period of 5 0 minutes formed 2 i layers, the barium 'postdodecylbene D sulfonate 1 layer being clear and there was very little emulsion meter the interface. When a sodiumsalt'ofa mahogany sulfonic acidhaving an average molecular weight 'of--500was substituted.fottheA'ZO molecular weight mahogany sulfonic acid, .the amount added was reduced to 8 parts. The emu-l sionbroke readily-and the overall resultsjwere somewhat better than when the 470 molecular weight sulfonate was used. T l a Calcium postdodecylbenzene sulfonate was prepared b'yiaiprocedure. which can be described as follows: a 25 percent. aqueous calcium chloride solution was added with agitationto. *a.30.percent. :active postdodecylbenzene sul-- "fonatexsoluticnrin x100 Pale .oil. A. total of 1 /2;

.hours, showed .little. tendency to separate. The experiment;

was .-then.r epeated with the exception that '5. weight percentof sodium salt of. a mahogany sulfonic acid having an. average molecular weight 0f..500 based on the .weight ot: the sodium postdodecylbenzene sulfonaterwas. added to the mixture. The resulting composition; brokeisharply. intotwo layers after standingforl hour. and-the upperv sulfonate layer. was; clear and ,therewas very little .ernul-. sion cufliat the interface. 7

' EXAMPLE 2 7 To illustrate the advantages of our compositions as an; emulsifier 'for white oil the following experiments were conduc'tednS parts ofa 6 percent activesodiurn postdodecylbenzene sulfonatesolution in white oilwas added to'45 parts of water. at.120'' C., shaken 20 times, allowed to stand 5 minutesiand then shaken an radditionalZQ times. The emulsion was evaluated. 1 5.. minutes after the second shaking. The foregoing .experimentwas repeated-using instead of thejS, parts of the sodium postdodecylbenzene sulfonate, 5 parts of a sulfonate' mixture containing vary: ing amounts of sodium postdodecylbenzene.sulfonatejplus varying amounts of Wo'sodiuinlmahogany.sulfonates, one a. the. sodium salt? of 'a .mahogany. sulfonic acid having an average molecular weight of 470 and the otheithesodium. salt of a mahoganysulfonic acid havin'g an average melee results aresummarized in Table "1 below;

ular weight of401iflhe experiments; ogtheithe Tablelf' i ndemve f V V Per- Wt. Per- 7 f Sample No. Wt. Per.- cent Na eentNa Emulsion; cent Na Vmahog mahog-. PDB' any.sul-. .any.sul-.

sull'onate fonate fonate v '(470- (405'- product) product) 100 A 0.0 0.0 Unstable 95. a 3.0 20 Fair.

' r 10 10.0 Good. 5Q; 25 25 Excellent."

EXAMPLE 3 In order to illustrate the value of the sulfonate mixtures as a lubricating oil detergent, the following experiments were conducted. Lubricating compositions were prepared by adding barium postdoclecylbenzene sulfonate to a blend of SAE 30 mineral oil. As a companion experiment lubricating compositions were prepared by adding barium postdodecylbenzene sulfonate containing varying amounts of a barium salt of a mahogany sulfonic acid having an average molecular Weight of 500 to a blend of SAE 30 mineral oil. The mixtures were heated to about 140 F. with agitation to obtain a uniform blend.

The lubricating compositions thus produced were subjected to cub engine tests. This test may be described briefly as follows: Four-cylinder Cub gasoline engines (Internationals light tractor engine adapted to a stand test) are run for 36 hours at 2,500 R. P. M. with 11 brake horsepower output, an oil temperature of 280 F., and a jacket temperature of 200 F. After completion of the run, the engines are disassembled and the parts are inspected and assigned demerit ratings based on their condition. The lower the total of demerit ratings, the better is the general engine condition and the oil performance. A rating below is considered to be excellent and a rating between 10 and 15 is good. Corrosion is also measured by weighing the hearing shells before and after the runs. The corrosion rating represents the loss of weight in grams per half bearing shell. A loss due to corrosion of less than 0.05 gram is considered to indicate good performance for the oil. The results of the Cub engine runs are shown below in the table.

While particular embodiments of the invention have been described, it will be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. The method of improving the surface active properties of a metal salt of an alkaryl sulfonic acid having an average molecular weight within the range of 425 to 475 by incorporating therein and based on the weight of said metal salt 3 to weight percent of a mixture, said mixture comprising 50 to Weight percent of a metal salt of a mahogany sulfonic acid having an average molecular weight within the range of 450 to 500 and 50 to 0 weight percent of a metal salt of a mahogany sulfonic acid having an average molecular weight within the range of 350 to 400 wherein the metal of said salts is selected from the group consisting of the alkali and alkaline earth metals.

2. The method of improving the surface active properties of a metal salt of an alkaryl sulfonic acid having an average molecular weight within the range of 425' to 476 by incorporating therein and based on said metal salt 3 to 50 weight percent of a metal salt of a mahogany sulfonic acid having an average molecular weight within the range of 450 to 5-00 wherein the metal of said salts is selected from the group consisting of the alkali and alkaline earth metals.

3. The process of claim 1 wherein the alkaryl sulfonic acid has an average molecular weight of 445'.

4. The process of claim 1 wherein the metal salt of said alkaryl sulfonic acid is sodium alkaryl sulfonate.

5. The process of claim 1 wherein the metal salt of said alkaryl sulfonic acid is calcium alkaryl sulfonate.

6. The process of claim 1 wherein the metal salt of said alkaryl sulfonic acid is barium alkaryl sulfonate.

7. The process of claim 1 wherein the first mentioned mahogany sulfonic acid has an average molecular weight of 500.

8. The process of claim 1 wherein the second mentioned mahogany sulfonic acid has an average molecular weight of 400.

References Cited in the file of this patent UNITED STATES PATENTS 2,391,087 Donlan et a1. Dec. 18, 1945 2,531,166 Shaw Nov. 21, 1950 2,566,298 Irwin Sept. 4, 1951 2,606,872 Gasser et a1 Aug. 12, 1952 

1. THE METHOD OF IMPROVING THE SURFACE ACTIVE PROPERTIES OF A METAL SALT OF AN ALKARYL SULFONIC ACID HAVING AN AVERAGE MOLECULAR WEIGHT WITHIN THE RANGE OF 425 TO 475 BY INCORPORATING THEREIN AND BASED ON THE WEIGHT OF SAID METAL SALT 3 TO 50 WEIGHT PERCENT OF A MIXTURE, SAID MIXTURE COMPRISING 50 TO 100 WEIGHT PERCENT OF A METAL SALT OF A MAHOGANY SULFONIC ACID HAVING AN AVERAGE MOLECULAR WEIGHT WITHIN THE RANGE OF 450 TO 500 AND 50 TO 0 WEIGHT PERCENT OF A METAL SALT OF A MAHOGANY SULFONIC ACID HAVING AN AVERAGE MOLECULAR WEIGHT WITHIN THE RANGE OF 350 TO 400 WHEREIN THE METAL OF SAID SALTS IS SELECTED FROM THE GROUP CONSISTING OF THE ALKALI AND ALKALINE EARTH METALS. 